29 Sep 20 Dry vs wet cleaning: pitfalls and solutions for optimal allergen control
Cleaning is one of the most crucial aspects of an effective allergen control programme. It aims to remove allergen soils from equipment and shared lines. Cleaning is regarded as the first line of defence against allergen contamination.
If not managed properly, the cleaning process itself can become a source of contamination. Therefore, cleaning must be planned, managed, validated and verified continually.
There are two types of cleaning used in the food industry: dry and wet cleaning methods.
Wet cleaning methods
Water can introduce all three cleaning energies (mechanical energy, thermal energy and chemical energy), and be used to flush away residues. However, water can not be used for cleaning in all cases. The decision regarding whether to use water is often a function of the water activity of the food being processed at that point.
Where possible, facilities that manufacture high-water-activity foods should be designed to accommodate water, with equipment that can be disassembled and electronics wired to either withstand or be protected from moisture.
The floors and walls should be designed with smooth surfaces to prevent adsorption of allergenic ingredients, and to allow for easy and effective cleaning. Floor drains should be available for drainage of water after wet cleaning.
Dry cleaning methods
Dry goods manufacturing environments are often not designed to accommodate water, or may even need to be free of water to facilitate manufacturing. For example, the presence of water could affect the quality and consistency of products such as bread, pastry, biscuits, cereals, chocolate, etc.
Furthermore, some processing equipment does not allow easy access for cleaning (e.g. chocolate enrobers and baking ovens).
Without the use of water for cleaning, manufacturers of dry goods face a challenge in removing allergenic food residues from processing equipment. Dry cleaning relies on the soil being physically removed using a limited number of methods, such as vacuuming, sweeping, scraping, wiping with cloths, brushes, compressed air, dry ice, material flushes, product purging, etc.
It is considered good practice to follow physical cleaning by wiping surfaces with wet cloths or wipes eg alcohol-based wet wipes.
Each method has its own set of pitfalls, and these must be considered when designing a cleaning programme.
FACTS (Food & Allergy Consulting & Testing Services) has created the infographic below [click to enlarge; download for optimal viewing] highlighting the pitfalls associated with the two types of cleaning, and giving some possible solutions to each.